I just encountered this issue and setting the transform of the Forest Pack object to 0,0,0 resolved the issue; 'surface' selected for the Forest Pack object is also at 0,0,0, but non-planar.
Corona version: 7
Full-speed, Non-debug, MaxSDK 2020
Build timestamp: Jul 20 2021 21:55:24
Forest Pro 7.1.1
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